Fossil remains from one of the largest meat-eating dinosaurs ever found have been identified as belonging to a new species.
Student Steve Brusatte, now at the University of Bristol, made the identification from several pieces of the skull found by Paul Sereno in the Republic of Niger in 1997.
The new dinosaur is called Carcharodontosaurus iguidensis and belongs to the meat-eating theropod dinosaurs - a group that also includes Tyrannosaurus rex - although it is more closely related to Allosaurus
The enormous beast would have been 13-14m long and was taller than a double-decker bus. Its skull was about 1.75m long and it had teeth as big as bananas.
The 95-million-year fossil is from the Cretaceous Period. It includes parts of the snout, lower jaw, braincase and part of the neck. There were a number of other huge theropods living at the same time in North Africa including the giant fish-eater called Spinosaurus
'The first remains of Carcharodontosaurus were found in the 1920s,' says Brusatte, 'but they only consisted of two teeth which have since been lost.'
'Other bits of Carcharodontosaurus were found in Egypt and described in the 1930s, but these were destroyed when Munich Museum was bombed in 1944.'
Since then Paul Sereno discovered an almost complete skull of Carcharodontosaurus saharicus in the Moroccan Sahara, which he described a decade ago. The evidence for this dinosaur therefore is very rare.
'This new find demonstrates that very large carnivorous dinosaurs were more widely distributed in Africa than previously suspected,' says Dr Angela Milner, dinosaur expert at the Natural History Museum.
'This new species of Carcharodontosaurus from Niger is very similar to Carcharodontosaurus saharicus , known from fragmentary material collected in the early 1900's from Egypt, and a complete skull found in Morocco about 10 years ago. '
'The two species, which were very similar in size and appearance, were living at approximately the same time but were apparently separated by a relatively shallow sea.'
'It may be that these giants arose by allopatric speciation, whereby biological populations are physically isolated by a barrier, in this case a seaway, and evolve in reproductive isolation. If the barrier breaks down later, individuals of the populations can no longer interbreed.'
'This is a well-recognised phenomenon in living animals but the same 'rules' almost certainly applied in the remote past as well. However, that hypothesis can't be tested with ancient fossils!'
The research is published this week in the latest issue of the Journal of Vertebrate Paleontology.